I agree, you'll be more efficient (regarding the amount of $ you wanna spend) if you build a wind tunnel.
As someone who is almost done building a wind tunnel for hosting around 150 SP30s, I agree. Unless you're buying mining hardware that comes without a heatsink and fan, you'll find it much cheaper to pass the heat from the ASIC to the heatsink to the air instead of from the ASIC to some expensive dielectric liquid to the heatsink to the air.